SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '2d41977ff675786df93c20fd208b2669f30aa465f4c3d05fb374279d14cf4a4d' 
  AND token = 'XYxbLQseR8ruOlhGFH9PlKZb5WEFZBwWjj2P10rBC9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}